1. Field of the Invention
The present invention generally involves the field of technology relating to chemical reactions known as oxidation-reduction reactions. More particularly, the invention relates to the activation of such reactions by electrochemically generated atomic hydrogen.
2. Description of the Prior Art
It is known to electrochemically generate hydrogen and either carbon dioxide or carbon monoxide gases through an oxidation-reduction reaction. This may be accomplished in an electrolytic cell environment by anodic oxidation of carbon and cathodic reduction of hydrogen ion in an aqueous acidic electrolyte. In this process, the anode is consummable and formed of an appropriate carbonaceous material, such as coal, lignite, active carbons, coke and the like. The cathode is not consummable and formed of copper, iron or other such suitable material. These electrodes are immersed in the aqueous acidic electrolyte contained within an electrolytic cell, wherein the latter is typically subdivided into separate anolyte and catholyte chambers by an ion permeable membrane or a porous barrier which prevents or minimizes mixing of the anolyte and catholyte portions of the electrolyte. When an electrical potential of sufficient voltage is applied across the electrodes from a direct current power source, oxidation of a carbonaceous anode produces oxides of carbon, and reduction of hydrogen ion at the cathode produces hydrogen.
It is also known that the aforedescribed electrochemical reaction may be catalyzed or otherwise improved through the addition of various agents to the electrolyte in order to affect the rate of oxidation of the carbonaceous material or to lower the half cell voltage required for oxidation to occur, thereby increasing the amount of current passed through the cell for a given operating voltage. Conventional electrochemical processes of this type have essentially been constrained to a strict adherence to Faraday's Law wherein, for a given amount of electrical current utilized to drive the reaction, a fixed maximum volume of gas can be generated when the operation is 100% efficient. This limitation has therefore rendered heretofore known techniques for the electrochemical gasification of carbonaceous materials impractical for the joint production of hydrogen and oxides of carbon. This is because, notwithstanding the utilization of catalyzed reactions, the volume of gas produced does not justify the cost of the electrical energy consumed.
In addition, the aforedescribed electrochemical reaction is a gasification reaction only. The objective of breaking the complex molecules present in coal, wood or other carbonaceous materials into desired liquid products useful in the chemical industry has not heretofore been realized electrochemically. A number of methods of coal liquefaction are available but are costly to operate and are therefore of questionable economic value. A low cost coal gasification and liquefaction process which can also be applied to other carbonaceous materials such as wood wastes, bagasse and other renewable resources would be a very useful addition to the chemical technology extant today.
It is well known that hydrogen electrochemically generated at a cathode is generated as H.degree. (atomic hydrogen) by the combination of an electron (e.sup.-) furnished by the cathode and a hydrogen ion (H.sup.+) furnished by the electrolyte. Hydrogen gas (H.sub.2) results from the combination of two units of atomic hydrogen to form the H.sub.2 molecule. Since H.sub.2 has limited solubility in aqueous electrolytes, it precipitates from solution to form H.sub.2 bubbles which rise to the surface of the electrolyte and may be collected as hydrogen gas. It is also known that electrochemically generated atomic hydrogen is a powerful, though very transient, chemical agent. It is thought to be an important intermediate in the chemical reduction of chromic acid during chromium electroplating from chromic acid solutions. Attempts have been made to diffuse electrochemically generated atomic hydrogen through metal tubes or membranes to emerge at a metal-solution interface where it will provide a desired chemical reaction. In general, these and other efforts to gain physical control of atomic hydrogen and allow its efficient use in desired chemical reactions have been unsuccessful as compared to other methods of carrying on the reactions. Even chromium plating is an inefficient example of the use of atomic hydrogen as the operation is only 14% to 18% efficient in electrochemical energy use. Thus the long sought after method of utilizing the powerful chemical activity of atomic hydrogen in a wide variety of chemical reactions has not been heretofore realized.